Genentech receives FDA approval for Perjeta to treat HER2-positive metastatic breast cancer

Intended for patients who have not received prior treatment for metastatic breast cancer with an anti-HER2 therapy or chemotherapy, Perjeta is combined with trastuzumab, another anti-HER2 therapy, and docetaxel, a type of chemotherapy.

HER2 is a protein involved in normal cell growth. It is found in increased amounts on some types of cancer cells (HER2-positive), including some breast cancers. In these HER2-positive breast cancers, the increased amount of the HER2 protein contributes to cancer cell growth and survival.

Perjeta is a humanized monoclonal antibody, manufactured through biotechnology methods. It is administered intravenously and is believed to work by targeting a different part of the HER-protein than trastuzumab, resulting in further reduction in growth and survival of HER2-positive breast cancer cells.

Because there are production issues that potentially could affect the long-term supply of the drug, FDA limited its approval today to drug product that has not been affected by those issues. Genentech, the manufacturer of Perjeta, has committed to take steps designed to resolve these production issues in a timely manner.

"Given the need for additional treatments for metastatic breast cancer, we made the decision to approve this drug today and not to delay its availability to patients pending resolution of the production issues relating to future supply," said Janet Woodcock, M.D., director of FDA's Center for Drug Evaluation and Research. "Genentech is currently developing a plan to mitigate the effect on patients of any potential shortage of Perjeta."

Breast cancer is the second leading cause of cancer-related death among women.  This year an estimated 226,870 women will be diagnosed with breast cancer, and 39,510 will die from the disease. About 20 percent of breast cancers have increased amounts of the HER2 protein.

"Since trastuzumab was first approved more than a decade ago, continued research has allowed us to better understand the role HER2 plays in breast cancer," said Richard Pazdur, M.D., director of the Office of Hematology and Oncology Products in the FDA's Center for Drug Evaluation and Research. "This research provided the background to combine two targeted drugs – trastuzumab and Perjeta with docetaxel to slow disease progression in breast cancer."

The safety and effectiveness of Perjeta were evaluated in a single clinical trial involving 808 patients with HER2-positive metastatic breast cancer who were tested prior to treatment to determine if the HER2 protein was increased. Patients were randomly assigned to receive Perjeta, trastuzumab and docetaxel or trastuzumab and docetaxel with a placebo.

The study was designed to measure the length of time a patient lived without the cancer progressing, progression-free survival (PFS). Those treated with the combination containing Perjeta had a median PFS of 18.5 months, while those treated with the combination containing placebo had a median PFS of 12.4.

The most common side effects observed in patients receiving Perjeta in combination with trastuzumab and docetaxel were diarrhea, hair loss, a decrease in infection-fighting white blood cells, nausea, fatigue, rash, and nerve damage (peripheral sensory neuropathy).

Perjeta is being approved with a Boxed Warning alerting patients and health care professionals to the potential risk of death or severe effects to a fetus. Pregnancy status must be verified prior to the start of Perjeta treatment.

The therapy was reviewed under the agency's priority review program, which provides for an expedited six-month review of drugs that may offer major advances in treatment.

Perjeta is marketed by South San Francisco-based Genentech, a member of the Roche Group.